Question about Telnet (jakarta commons or general)

Question

Sorry if I ask some basic questions but I am still learning.
With Telnet (or a Socket), you basically will open the Telnet - IP address and the port. One question, why is 23 used a lot? Anyhow, after opening it I would have to read the inputstream for "Login" then send it the login name, then read the inputstream for "Password" then send it the password?
Also I tried to use the Runtime.exec() to just execute telnet and sent an array of commands which included "telnet" "login" and "password" but I assume that was incorrect way of doing it, huh?

Answer 1

With Telnet (or a Socket), you basically will open
the Telnet - IP address and the port.The IP address is the IP of the host you wish to connect to . The port is a port where that host has a telnet server listening.
One question,
why is 23 used a lot?It was chosen as the default port for the telnet service by whatever standards body or other group selected these things.
When you enter a URL in your browser, you can explicitly specify a port. You normally don't because port 80 is the default, so that's what most web servers listen on.
Anyhow, after opening it I
would have to read the inputstream for "Login" then
send it the login name, then read the inputstream for
"Password" then send it the password? It wouldn't be two different input streams. You would just read from an input stream and write to an output stream.
Also I tried to use the Runtime.exec() to just
execute telnet and sent an array of commands which
included "telnet" "login" and "password" but I assume
that was incorrect way of doing it, huh?I don't know what the problem is, as I haven't seen your code and am not intimately familiar with the details of the telnet protocol. Google for telnet protocol spec or something like that and you shoud find all the gory details.
I haven't used the Net module from jakarta, but I expect it would hide a lot of that low-level detail from you.